GB/T 11299.7-1989 Satellite communication earth station radio equipment measurement methods Part 2: Subsystem measurement Section 3: Low noise amplifier
Some standard content:
National Standard of the People's Republic of China
Methods of measurement for radio equipment used in satellite earth stationsPart 2:Sub-systems measuresSection Three-Low noise amplifierThis standard is one of the series of standards for "Methods of measurement for radio equipment used in satellite earth stations". 1 Subject content and scope of application
GB11299.789
This standard specifies the electrical performance measurement methods for low noise amplifiers and low noise blocks LNB (LowNoiseBlock) installed behind the antenna of satellite communication earth stations.
The measurement items are not necessarily limited to the contents of this standard. When additional measurements are required, they should be agreed upon by the relevant parties. 2 Overview
The input and output ports of the amplifier must be marked. Any auxiliary networks, such as RF filters, RF switches or inter-couplers, should also be described. The interface locations of these subsystems should be unified. Unless otherwise specified or agreed, the test signal level applied to the input of the low noise amplifier should be close to its working level. Or it should be low enough to ensure that the amplifier does not suffer gain compression or damage. When the low noise amplifier switches from one signal source or load to another, and when it is overloaded to the specified limit, the electrical performance should remain stable; when the conversion is completed or the overload signal is eliminated, the amplifier should automatically return to the original stable working state. 3 Power gain
See Chapter 5 of "Measurements within the radio frequency range" in this series of standards GB11299.2. If necessary, the input signal can be gradually increased from a low level to the maximum operating level to obtain the relationship curve between the output level and the input level. Based on this curve, the gain compression characteristics and saturation level of the amplifier can be obtained. 4 Gain instability
4.1 Definition
Gain instability is defined as: the change of the actual gain deviating from the nominal gain over time at a given frequency, which is usually divided into short-term (about minutes) instability, medium-term (about one hour) instability, and long-term (about one day) instability. 4.2 Measurement method
In addition to adding an XY recorder to the measurement equipment configuration to record the gain Except for the change with time, the measurement method is the same as the power gain measurement method in Section 5.2 of Part 1, Section 2 "Measurements in the radio frequency range" of this series of standards. If necessary, the measurement can be repeated several times at a given input frequency.
Approved by the Ministry of Electronics Industry of the People's Republic of China on March 1, 198976
Implementation on January 1, 1990
4.3 Result expression
GB11299.7-89
Describe the gain change at a given frequency and time by curve or text. 4.4 Required details
When this measurement is required, the equipment technical specifications should include the following: input test signal frequency;
h. Environmental conditions;
Measurement time and time interval.
5 Amplitude/frequency characteristics
5.1 Definition
The amplitude/frequency characteristics are defined as: when the input level remains constant, the ratio of the output level to the reference level (expressed in decibels) and the frequency. The reference level refers to the output level at a given frequency. The frequency of the input signal and the frequency of the output signal can differ by a fixed value. This definition only applies to linear or quasi-linear amplifiers and low-noise combinations. 5.2 Measurement method
The swept frequency measurement method is preferred, as shown in Figure 1. The point-by-point measurement method can also be used, but it is time-consuming, and the amplitude may change between the selected frequency points, and these changes may not be detected. The swept frequency method and point-by-point measurement method are not suitable. Both methods can use radio frequency or intermediate frequency replacement technology. 5.3 Result Representation
When using the swept frequency measurement method, the measurement results should be represented by photos or curves. When the measurement results are not represented graphically, they should be represented as follows: "The amplitude/frequency characteristics are within the range of 3.7 to 4.2 GHz, relative to the amplitude of 3.95 GHz, within +0.3~~-0.6d3". When measuring by the point measurement method, the measurement results can be tabulated or expressed in text. When there are obvious fluctuations in the measured characteristics, their peak-to-peak amplitude (decibel) and the corresponding frequency band should be indicated. 5.4 Details to be Specified
When this measurement is required, the equipment technical requirements should include the following: allowable amplitude variation range;
b. Frequency range;
reference frequency.
6 Noise temperature
6.1 Definition
The noise temperature of a low noise amplifier is defined as the equivalent noise temperature (T) of the amplifier input terminal I1, in K. 6.2 Measurement method
Since the low noise temperature is measured, it is recommended to use the hot/cold load method (Y factor method), and the intermediate frequency variable attenuator method is recommended, as shown in Figure 2.
The noise temperature of a low noise amplifier should be measured at the specified frequency within the specified passband. The noise temperature measured at each frequency point is actually the average noise temperature. In order to ensure the authenticity of the measurement results, when measuring the noise at the upper and lower limit frequency points of the low noise amplifier passband, the local oscillator frequency of the test system should be selected as follows: when measuring at the lower limit of the passband, a high local oscillator rate is selected; when measuring at the upper limit of the passband, a low local oscillator frequency is selected. Because the noise temperature of the amplifier under test is determined based on its input port, the calculation should also be based on the hot and cold load noise temperatures of the port. If there are transmission lines or other devices between the hot and cold loads and the amplifier under test, their influence must be considered. The measurement steps are as follows: a. Referring to Figure 2, connect the cold load to the input port of the amplifier under test, adjust the precision variable attenuator so that the indicator gets a reading close to the full scale of 1., record I. and the attenuator reading A expressed in decibels. b. Disconnect the cold load, connect the hot load to the input port of the amplifier under test, adjust the precision variable attenuator so that the indicator gets a reading close to the full scale of 1., and record the attenuator reading Ah expressed in decibels. The Y factor expressed in decibels is given by the following formula: Y(dB) =- P,(dB) - P(dB) --- A,(dB) - A,(dB) Where: Ih and P.
When the input port of the amplifier under test is connected to the hot and cold loads respectively, the noise power at its output port. According to Y(dB), the Y factor is obtained:
Knowing the Y factor, the equivalent input noise temperature (T.) of the amplifier under test can be calculated by formula (3): T
Where: T——noise temperature of hot load; T. ·-noise temperature of cold load.
6.3 Result representation
T,-Yre
·（3）
The measurement results are plotted with the equivalent input noise temperature (T.) as the ordinate and the test frequency (f) as the abscissa, and a curve or table is drawn. 6.4 Details to be specified
When this measurement is required, the equipment specifications shall include the following: a.
The accuracy of the required measurement equipment configuration;
The frequency range over which the measurement is to be made;
The maximum input level applied to the amplifier under test. 7 Input and output return loss
7.1 Definitions and general considerations
The input (or output) return loss (L) or voltage standing wave ratio (VSWR) of a low noise amplifier is a measure of the degree of match between its input (or output) impedance (Z) and the nominal impedance (Z.). The return loss (1.) is given by the following equation: L 20log1
It can also be expressed as:
L = 20 log1o
Where: p
The voltage reflection coefficient of the impedance (Z) with respect to the nominal impedance (Z.); zz.
The relationship between the co-wave loss (L) and the voltage standing wave ratio (VSWR) is as follows: 7.2 Measurement method
1. = 20 logioVSWR 1
VSWR + 1
（6）
Can be measured by sweep frequency method or point-by-point measurement method, but the point-by-point measurement method requires a large number of measurements and is time-consuming. Both measurement methods can use measurement line technology or reflectometer technology. When using high-precision measurement equipment, the accuracy of the measured voltage standing wave ratio is about 0).01 or less.
Figure 3 shows the typical equipment configuration for measuring return loss with a reflectometer. A four-port directional coupler is used to obtain samples of the incident power and the reflected power, and the amplitude of the reflection coefficient at each frequency is measured. In order to calibrate the test equipment, a short circuit is used to replace the amplifier under test, and the attenuator is adjusted to simulate a known return loss. For example, 26c178
GB11299.7---89
attenuation corresponds to a 26dB return loss. This calibration method is more desirable than the method that requires knowing the detection law. If the level of the incident wave is not constant in the measured frequency band, the calibration should be adjusted to record the calibration curve under the relevant conditions. Note: <1 The achievable accuracy is determined by the degree to which the directional network directional performance exceeds the measured return loss. For example, 40dB directional performance enables the measurement accuracy of the measured 26dB inter-wave loss to reach -1.6 to +1.9dI3. (2) If the reflectometer can measure amplitude and phase simultaneously, it can be used to display the impedance circle diagram. 7.3 Presentation of results
The measurement results shall be presented as a curve or a photograph of a calibrated oscilloscope display. When the measurement results are not presented graphically, they shall be presented as follows: "Input return loss is less than 20 dB in the range of 3.7 to 4.2 GHz". The maximum error in all cases shall be given. 7.4 Details to be specified
When this measurement is required, the following shall be included in the equipment specifications: a. Nominal impedance;
b. Minimum permissible return loss;
c. Frequency range.
8 Effect of out-of-band signals on gain compression and noise temperature 8.1 Definitions and general considerations
Out-of-band signals mainly refer to the signals leaked from the transmitter and other interfering signals whose frequencies are outside the passband of the low noise amplifier. Out-of-band signals will cause gain compression of the noise amplifier and increase its noise temperature. The degree of influence depends on the frequency and level of the out-of-band signals. 8.2 Measurement method
Use a suitable directional network to add the out-of-band signal of the specified frequency and level to the input of the amplifier together with the required test signal. As shown in Figure 4, the
measurement steps can be carried out in accordance with Chapter 3 and Chapter 6 of this standard. 8.3 Result Expression
The measurement result shall be expressed as follows:
*When the input frequency is 6.225GHz and the level is 0dBm of the out-of-band signal, the gain of the amplifier is compressed by 0.2dB and the noise temperature increases by 3.5K".
8.4 Details to be Specified
When this measurement is required, the equipment technical specifications shall include the following: a. The frequency range and level of the out-of-band signal; b. The maximum values of the gain compression and noise temperature increase allowed. 9 Group Delay/Frequency Characteristics
See Chapter 7 of "Measurements within the Radio Frequency Range" of this series of standards GB11299.2. 10 Multi-Carrier Intermodulation Ratio
See Chapter 8 of "Measurements within the Radio Frequency Range" of this series of standards GB11299.2. When measuring low-level intermodulation products, the RF load connected to the first fixed coupler in Figure 8+ of Section 2 of Part 1 of this series of standards "Measurements within the Radio Frequency Range" can be changed to a cold load to reduce the residual noise level. 11 AM/PM conversion coefficient
11.1 Definition
CB11299.789
The AM/PM conversion coefficient is defined as: the -th derivative of the phase shift of the output signal with respect to the input signal level when the input frequency is given. It is expressed in degrees/decibels.
11.2 Measurement method
The AM/PM conversion coefficient can be measured by static method or dynamic method. The static method is recommended because its measurement equipment configuration is simpler and the phase shift error caused by the level change of the measurement equipment itself is also easy to calibrate. The measurement equipment configuration is shown in FIG5, in which a suitable phase meter, such as a network analyzer or a vector voltmeter, is used to detect the phase change of the output signal of the amplifier under test caused by the input signal level change (e.g., 1.0 dB). Before making the measurement, the phase shift error caused by the measuring equipment itself (especially the attenuator and phase meter) due to the level change should be determined. In order to minimize the phase shift caused by the measuring equipment, a suitable attenuator, such as a waveguide rotary precision attenuator, should be used. 11.3 Presentation of results
The measurement results are expressed in degrees/dB, preferably as a curve of the relationship between the amplitude modulation/phase modulation conversion coefficient and the input signal level at each given frequency.
11.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a. The measurement method used;
b. The level and frequency of the input RF signal; the maximum amplitude modulation/phase modulation conversion coefficient allowed. c.
12 Effect of ambient temperature on gain and noise temperature 12.1 Definitions and general considerations
The effect of ambient temperature on the gain and noise temperature of a low noise amplifier refers to the change of the actual gain and noise temperature with temperature within the specified temperature range, which deviates from the nominal value (measured at the specified room temperature). 12.2 Measurement method
Except for the requirement that the amplifier under test be placed in a temperature-adjustable incubator, refer to Chapters 3 and 6 of this standard for the rest. 12.3 Representation of results
The measurement results are best presented as curves.
When the measurement results are not presented graphically, they should be presented as follows: "Over the temperature range of -40 to +55°C, the gain variation is less than (or equal to) ±1.5 dB, and the noise temperature variation is less than (or equal to) ±20 K."
12.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a. The measurement method required:
The allowable gain and noise temperature variations; the temperature range of the measurement;
The measured Frequency range.
Sweep frequency signal
Generator
Precision variable
Attenuator
Amplifier
Detector
Figure 1 Equipment for measuring amplitude/frequency characteristics using the swept frequency method, equipped with an XY recorder
or an XY recorder
Hot load
Cold load
Amplifier
GB11299.7
Down-conversion
Precision variable
Attenuator
Telephone
Indicator
Figure 2 Equipment for measuring hot/cold load Y-factor intermediate frequency variable attenuator method, equipped with an XY recorder
Sweep signal
Generator
Automatic level control
（ (as required)
Frequency signal
Generator
Attenuator
Hot: cold
Isolator
Detector
Filter
Transmitted power
Input monitoring
(as required)
Transmitted variable
Attenuator
Reflected power defect sample
Reflective coupler
(Reflectometer)
Detector and
Filter
Reflectometer Typical equipment configuration for measuring return loss RF converter switch
Generator
Isolator
Amplifier
RF converter switch
Down converter|| |tt||Amplifier
Use a short circuit
Replace the amplifier under test
Borne wave or
Detector
Precision variable
Attenuator
Figure 4 Typical equipment configuration for measuring the influence of out-of-band signals on gain and noise temperature XY
Recorder
Signal center
Indicator
Additional instructions:
Generator
Coupler
GB11299.7-89
Variable RF
Attenuator
Amplifier
Equipment configuration for measuring AM/PM conversion coefficient by static method Figure 5
This standard was drafted by the 54th Institute of the Ministry of Electronics Industry. 82
Phase meter3. Presentation of results
The measurement results shall be presented as a curve or a photograph of a calibrated oscilloscope display. When the measurement results are not presented graphically, they shall be presented as follows: "Input return loss is less than 20 dB in the range of 3.7 to 4.2 GHz". The maximum error in all cases shall be given. 7.4. Details to be specified
When this measurement is required, the following shall be included in the equipment specifications: a. Nominal impedance;
b. Minimum permissible return loss;
c. Frequency range.
8. Effect of out-of-band signals on gain compression and noise temperature 8.1. Definitions and general considerations
Out-of-band signals mainly refer to the signals leaked from the transmitter and other interfering signals whose frequencies are outside the passband of the low noise amplifier. Out-of-band signals will cause gain compression of the noise amplifier and increase its noise temperature. The degree of influence depends on the frequency and level of the out-of-band signals. 8.2 Measurement method
Use a suitable directional network to add the out-of-band signal of the specified frequency and level to the input of the amplifier together with the required test signal. As shown in Figure 4, the
measurement steps can be carried out in accordance with Chapter 3 and Chapter 6 of this standard. 8.3 Result Expression
The measurement result shall be expressed as follows:
*When the input frequency is 6.225GHz and the level is 0dBm of the out-of-band signal, the gain of the amplifier is compressed by 0.2dB and the noise temperature increases by 3.5K".
8.4 Details to be Specified
When this measurement is required, the equipment technical specifications shall include the following: a. The frequency range and level of the out-of-band signal; b. The maximum values of the gain compression and noise temperature increase allowed. 9 Group Delay/Frequency Characteristics
See Chapter 7 of "Measurements within the Radio Frequency Range" of this series of standards GB11299.2. 10 Multi-Carrier Intermodulation Ratio
See Chapter 8 of "Measurements within the Radio Frequency Range" of this series of standards GB11299.2. When measuring low-level intermodulation products, the RF load connected to the first fixed coupler in Figure 8+ of Section 2 of Part 1 of this series of standards "Measurements within the Radio Frequency Range" can be changed to a cold load to reduce the residual noise level. 11 AM/PM conversion coefficient
11.1 Definition
CB11299.789
The AM/PM conversion coefficient is defined as: the -th derivative of the phase shift of the output signal with respect to the input signal level when the input frequency is given. It is expressed in degrees/decibels.
11.2 Measurement method
The AM/PM conversion coefficient can be measured by static method or dynamic method. The static method is recommended because its measurement equipment configuration is simpler and the phase shift error caused by the level change of the measurement equipment itself is also easy to calibrate. The measurement equipment configuration is shown in FIG5, in which a suitable phase meter, such as a network analyzer or a vector voltmeter, is used to detect the phase change of the output signal of the amplifier under test caused by the input signal level change (e.g., 1.0 dB). Before making the measurement, the phase shift error caused by the measuring equipment itself (especially the attenuator and phase meter) due to the level change should be determined. In order to minimize the phase shift caused by the measuring equipment, a suitable attenuator, such as a waveguide rotary precision attenuator, should be used. 11.3 Presentation of results
The measurement results are expressed in degrees/dB, preferably as a curve of the relationship between the amplitude modulation/phase modulation conversion coefficient and the input signal level at each given frequency.
11.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a. The measurement method used;
b. The level and frequency of the input RF signal; the maximum amplitude modulation/phase modulation conversion coefficient allowed. c.
12 Effect of ambient temperature on gain and noise temperature 12.1 Definitions and general considerations
The effect of ambient temperature on the gain and noise temperature of a low noise amplifier refers to the change of the actual gain and noise temperature with temperature within the specified temperature range, which deviates from the nominal value (measured at the specified room temperature). 12.2 Measurement method
Except for the requirement that the amplifier under test be placed in a temperature-adjustable incubator, refer to Chapters 3 and 6 of this standard for the rest. 12.3 Representation of results
The measurement results are best presented as curves.
When the measurement results are not presented graphically, they should be presented as follows: "Over the temperature range of -40 to +55°C, the gain variation is less than (or equal to) ±1.5 dB, and the noise temperature variation is less than (or equal to) ±20 K."
12.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a. The measurement method required:
The allowable gain and noise temperature variations; the temperature range of the measurement;
The measured Frequency range.
Sweep frequency signal
Generator
Precision variable
Attenuator
Amplifier
Detector
Figure 1 Equipment for measuring amplitude/frequency characteristics using the swept frequency method, equipped with an XY recorder
or an XY recorder
Hot load
Cold load
Amplifier
GB11299.7
Down-conversion
Precision variable
Attenuator
Telephone
Indicator
Figure 2 Equipment for measuring hot/cold load Y-factor intermediate frequency variable attenuator method, equipped with an XY recorder
Sweep signal
Generator
Automatic level control
（ (as required)
Frequency signal
Generator
Attenuator
Hot: cold
Isolator
Detector
Filter
Transmitted power
Input monitoring
(as required)
Transmitted variable
Attenuator
Reflected power defect sample
Reflective coupler
(Reflectometer)
Detector and
Filter
Reflectometer Typical equipment configuration for measuring return loss RF converter switch
Generator
Isolator
Amplifier
RF converter switch
Down converter|| |tt||Amplifier
Use a short circuit
Replace the amplifier under test
Borne wave or
Detector
Precision variable
Attenuator
Figure 4 Typical equipment configuration for measuring the influence of out-of-band signals on gain and noise temperature XY
Recorder
Signal center
Indicator
Additional instructions:
Generator
Coupler
GB11299.7-89
Variable RF
Attenuator
Amplifier
Equipment configuration for measuring AM/PM conversion coefficient by static method Figure 5
This standard was drafted by the 54th Institute of the Ministry of Electronics Industry. 82
Phase meter3. Presentation of results
The measurement results shall be presented as a curve or a photograph of a calibrated oscilloscope display. When the measurement results are not presented graphically, they shall be presented as follows: "Input return loss is less than 20 dB in the range of 3.7 to 4.2 GHz". The maximum error in all cases shall be given. 7.4. Details to be specified
When this measurement is required, the following shall be included in the equipment specifications: a. Nominal impedance;
b. Minimum permissible return loss;
c. Frequency range.
8. Effect of out-of-band signals on gain compression and noise temperature 8.1. Definitions and general considerations
Out-of-band signals mainly refer to the signals leaked from the transmitter and other interfering signals whose frequencies are outside the passband of the low noise amplifier. Out-of-band signals will cause gain compression of the noise amplifier and increase its noise temperature. The degree of influence depends on the frequency and level of the out-of-band signals. 8.2 Measurement method
Use a suitable directional network to add the out-of-band signal of the specified frequency and level to the input of the amplifier together with the required test signal. As shown in Figure 4, the
measurement steps can be carried out in accordance with Chapter 3 and Chapter 6 of this standard. 8.3 Result Expression
The measurement result shall be expressed as follows:
*When the input frequency is 6.225GHz and the level is 0dBm of the out-of-band signal, the gain of the amplifier is compressed by 0.2dB and the noise temperature increases by 3.5K".
8.4 Details to be Specified
When this measurement is required, the equipment technical specifications shall include the following: a. The frequency range and level of the out-of-band signal; b. The maximum values of the gain compression and noise temperature increase allowed. 9 Group Delay/Frequency Characteristics
See Chapter 7 of "Measurements within the Radio Frequency Range" of this series of standards GB11299.2. 10 Multi-Carrier Intermodulation Ratio
See Chapter 8 of "Measurements within the Radio Frequency Range" of this series of standards GB11299.2. When measuring low-level intermodulation products, the RF load connected to the first fixed coupler in Figure 8+ of Section 2 of Part 1 of this series of standards "Measurements within the Radio Frequency Range" can be changed to a cold load to reduce the residual noise level. 11 AM/PM conversion coefficient
11.1 Definition
CB11299.789
The AM/PM conversion coefficient is defined as: the -th derivative of the phase shift of the output signal with respect to the input signal level when the input frequency is given. It is expressed in degrees/decibels.
11.2 Measurement method
The AM/PM conversion coefficient can be measured by static method or dynamic method. The static method is recommended because its measurement equipment configuration is simpler and the phase shift error caused by the level change of the measurement equipment itself is also easy to calibrate. The measurement equipment configuration is shown in FIG5, in which a suitable phase meter, such as a network analyzer or a vector voltmeter, is used to detect the phase change of the output signal of the amplifier under test caused by the input signal level change (e.g., 1.0 dB). Before making the measurement, the phase shift error caused by the measuring equipment itself (especially the attenuator and phase meter) due to the level change should be determined. In order to minimize the phase shift caused by the measuring equipment, a suitable attenuator, such as a waveguide rotary precision attenuator, should be used. 11.3 Presentation of results
The measurement results are expressed in degrees/dB, preferably as a curve of the relationship between the amplitude modulation/phase modulation conversion coefficient and the input signal level at each given frequency.
11.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a. The measurement method used;
b. The level and frequency of the input RF signal; the maximum amplitude modulation/phase modulation conversion coefficient allowed. c.
12 Effect of ambient temperature on gain and noise temperature 12.1 Definitions and general considerations
The effect of ambient temperature on the gain and noise temperature of a low noise amplifier refers to the change of the actual gain and noise temperature with temperature within the specified temperature range, which deviates from the nominal value (measured at the specified room temperature). 12.2 Measurement method
Except for the requirement that the amplifier under test be placed in a temperature-adjustable incubator, refer to Chapters 3 and 6 of this standard for the rest. 12.3 Representation of results
The measurement results are best presented as curves.
When the measurement results are not presented graphically, they should be presented as follows: "Over the temperature range of -40 to +55°C, the gain variation is less than (or equal to) ±1.5 dB, and the noise temperature variation is less than (or equal to) ±20 K."
12.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a. The measurement method required:
The allowable gain and noise temperature variations; the temperature range of the measurement;
The measured Frequency range.
Sweep frequency signal
Generator
Precision variable
Attenuator
Amplifier
Detector
Figure 1 Equipment for measuring amplitude/frequency characteristics using the swept frequency method, equipped with an XY recorder
or an XY recorder
Hot load
Cold load
Amplifier
GB11299.7
Down-conversion
Precision variable
Attenuator
Telephone
Indicator
Figure 2 Equipment for measuring hot/cold load Y-factor intermediate frequency variable attenuator method, equipped with an XY recorder
Sweep signal
Generator
Automatic level control
（ (as required)
Frequency signal
Generator
Attenuator
Hot: cold
Isolator
Detector
Filter
Transmitted power
Input monitoring
(as required)
Transmitted variable
Attenuator
Reflected power defect sample
Reflective coupler
(Reflectometer)
Detector and
Filter
Reflectometer Typical equipment configuration for measuring return loss RF converter switch
Generator
Isolator
Amplifier
RF converter switch
Down converter|| |tt||Amplifier
Use a short circuit
Replace the amplifier under test
Borne wave or
Detector
Precision variable
Attenuator
Figure 4 Typical equipment configuration for measuring the influence of out-of-band signals on gain and noise temperature XY
Recorder
Signal center
Indicator
Additional instructions:
Generator
Coupler
GB11299.7-89
Variable RF
Attenuator
Amplifier
Equipment configuration for measuring AM/PM conversion coefficient by static method Figure 5
This standard was drafted by the 54th Institute of the Ministry of Electronics Industry. 82
Phase meter2 "Measurements within the RF range" Chapter 7. 10 Multi-carrier intermodulation ratio
See this series of standards GB11299.2 "Measurements within the RF range" Chapter 8. When measuring low-level intermodulation products, the RF load connected to the first fixed coupler in Figure 8 of Part 1, Section 2 "Measurements within the RF range" of this series of standards can be changed to a cold load to reduce the residual noise level. 11 AM/PM conversion coefficient
11.1 Definition
CB11299.789
The AM/PM conversion coefficient is defined as: when the input frequency is given, the first-order derivative of the phase shift of the output signal to the input signal level. Expressed in degrees/dB.
11.2 Measurement Measurement method
The amplitude modulation/phase modulation conversion coefficient can be measured by static method or dynamic method. The static method is recommended because its measurement equipment configuration is simpler and the phase shift error caused by the level change of the measurement equipment itself is easy to calibrate. The measurement equipment configuration is shown in Figure 5, in which a suitable phase meter, such as a network analyzer or a voltmeter, is used to detect the phase change of the output signal of the amplifier under test caused by the input signal level change (for example, 1.0dB). Before measuring, the phase shift error caused by the level change of the measurement equipment itself (especially the attenuator and phase meter) should be determined. In order to minimize the phase shift caused by the measurement equipment, a suitable Suitable attenuators, such as waveguide rotary precision attenuators 11.3 Presentation of results
The measurement results shall be expressed in degrees/dB, preferably as a curve of the relationship between the amplitude modulation/phase modulation conversion coefficient and the input signal level at each given frequency.
11.4 Details to be specified
When this measurement is required, the equipment specifications shall include the following: a. The measurement method used;
b. The level and frequency of the input RF signal; the maximum allowable amplitude modulation/phase modulation conversion coefficient. c.
12 Effect of ambient temperature on gain and noise temperature 12.1 Definitions and general considerations
Environment The effect of temperature on the gain and noise temperature of a low noise amplifier refers to the change of the actual gain and noise temperature that deviates from the nominal value (measured at the specified room temperature) with temperature within the specified temperature range. 12.2 Measurement method
Except that the amplifier under test needs to be placed in a temperature-adjustable incubator, please refer to Chapter 3 and Chapter 6 of this standard. 12.3 Result representation
The measurement results are best represented by a curve.
When the measurement results are not represented graphically, they should be represented as follows: "Within the temperature range of -40~~+55C, the gain change is less than (or equal to) ±1.5dB, and the noise temperature change is less than (or equal to) ± 20K".
12.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a.
Measurement method:
Allowed gain and noise temperature changes; Measurement temperature range;
Measurement frequency range.
Swept frequency signal
Generator
Precision variable
Attenuator
Amplifier
Detector
Figure 1 Equipment for measuring amplitude/frequency characteristics using the swept frequency method Equipped with a gyroscope
or an XY recorder
Heat load
Cold Load
Amplifier
GB11299.7
Down-conversion
Precision variable
Attenuator
Telecommunications
Indicator
Figure 2 Measurement equipment for hot/cold load Y-factor intermediate frequency variable attenuator method Sweep signal
Generator
Automatic level control
(according to setting)
Frequency signal
Generator
Attenuator
Hot: cold
Isolator
Detector
Filter
Reflection power Frequency
Input monitoring
(set as needed)
Variable
Attenuator
Reflected power defect sample
Directional coupler
(Reflectometer)
Detector and
Filter
ReflectometerTypical equipment configuration for measuring return lossRF converter
Generator
Isolator
Amplifier
RF converter
Down converter
Amplifier
Use a short circuit
Replace the amplifier under test during calibration
wave detector
precision variable
attenuator
Figure 4 Typical equipment configuration for measuring the influence of out-of-band signals on gain and noise temperature XY
recorder
signal
indicator
additional instructions:
generator
coupler
GB11299.7-89
variable RF
attenuator
amplifier
equipment configuration for measuring AM/PM conversion coefficient by static method Figure 5
This standard was drafted by the 54th Institute of the Ministry of Electronics Industry. 82
Phase meter2 "Measurements within the RF range" Chapter 7. 10 Multi-carrier intermodulation ratio
See this series of standards GB11299.2 "Measurements within the RF range" Chapter 8. When measuring low-level intermodulation products, the RF load connected to the first fixed coupler in Figure 8 of Part 1, Section 2 "Measurements within the RF range" of this series of standards can be changed to a cold load to reduce the residual noise level. 11 AM/PM conversion coefficient
11.1 Definition
CB11299.789
The AM/PM conversion coefficient is defined as: when the input frequency is given, the first-order derivative of the phase shift of the output signal to the input signal level. Expressed in degrees/dB.
11.2 Measurement Measurement method
The amplitude modulation/phase modulation conversion coefficient can be measured by static method or dynamic method. The static method is recommended because its measurement equipment configuration is simpler and the phase shift error caused by the level change of the measurement equipment itself is easy to calibrate. The measurement equipment configuration is shown in Figure 5, in which a suitable phase meter, such as a network analyzer or a voltmeter, is used to detect the phase change of the output signal of the amplifier under test caused by the input signal level change (for example, 1.0dB). Before measuring, the phase shift error caused by the level change of the measurement equipment itself (especially the attenuator and phase meter) should be determined. In order to minimize the phase shift caused by the measurement equipment, a suitable Suitable attenuators, such as waveguide rotary precision attenuators 11.3 Presentation of results
The measurement results shall be expressed in degrees/dB, preferably as a curve of the relationship between the amplitude modulation/phase modulation conversion coefficient and the input signal level at each given frequency.
11.4 Details to be specified
When this measurement is required, the equipment specifications shall include the following: a. The measurement method used;
b. The level and frequency of the input RF signal; the maximum allowable amplitude modulation/phase modulation conversion coefficient. c.
12 Effect of ambient temperature on gain and noise temperature 12.1 Definitions and general considerations
Environment The effect of temperature on the gain and noise temperature of a low noise amplifier refers to the change of the actual gain and noise temperature that deviates from the nominal value (measured at the specified room temperature) with temperature within the specified temperature range. 12.2 Measurement method
Except that the amplifier under test needs to be placed in a temperature-adjustable incubator, please refer to Chapter 3 and Chapter 6 of this standard. 12.3 Result representation
The measurement results are best represented by a curve.
When the measurement results are not represented graphically, they should be represented as follows: "Within the temperature range of -40~~+55C, the gain change is less than (or equal to) ±1.5dB, and the noise temperature change is less than (or equal to) ± 20K".
12.4 Details to be specified
When this measurement is required, the equipment specifications should include the following: a.
Measurement method:
Allowed gain and noise temperature changes; Measurement temperature range;
Measurement frequency range.
Swept frequency signal
Generator
Precision variable
Attenuator
Amplifier
Detector
Figure 1 Equipment for measuring amplitude/frequency characteristics using the swept frequency method Equipped with a gyroscope
or an XY recorder
Heat load
Cold Load
Amplifier
GB11299.7
Down-conversion
Precision variable
Attenuator
Telecommunications
Indicator
Figure 2 Measurement equipment for hot/cold load Y-factor intermediate frequency variable attenuator method Sweep signal
Generator
Automatic level control
(according to setting)
Frequency signal
Generator
Attenuator
Hot: cold
Isolator
Detector
FilterWww.bzxZ.net
Reflection power Frequency
Input monitoring
(set as needed)
Variable
Attenuator
Reflected power defect sample
Directional coupler
(Reflectometer)
Detector and
Filter
ReflectometerTypical equipment configuration for measuring return lossRF converter
Generator
Isolator
Amplifier
RF converter
Down converter
Amplifier
Use a short circuit
Replace the amplifier under test during calibration
wave detector
precision variable
attenuator
Figure 4 Typical equipment configuration for measuring the influence of out-of-band signals on gain and noise temperature XY
recorder
signal
indicator
additional instructions:
generator
coupler
GB11299.7-89
variable RF
attenuator
amplifier
equipment configuration for measuring AM/PM conversion coefficient by static method Figure 5
This standard was drafted by the 54th Institute of the Ministry of Electronics Industry. 82
Phase meter7
Down conversion
Precision variable
Attenuator
Telecommunications
Indicator
Figure 2 Measurement equipment for hot/cold load Y-factor intermediate frequency variable attenuator method Sweep signal
Generator
Automatic level control
(according to setting)
Frequency signal
Generator
Attenuator
Hot: Cold
Isolator
Detector
Filter
Transmitted power
Input monitoring
(Set as needed)
Variable transmit
Attenuator
Reflected power defect sample
Directional coupler
(Reflectometer)
Detector and
Filter
ReflectometerTypical equipment configuration for measuring return lossRF converter
|Switch
Generator
Isolator
Amplifier
RF to
Switch
Downconverter
Amplifier
Use a short-circuit device to replace the amplifier under test during calibration
Amplifier or
Detector
Precision variable
Attenuator
Figure 4 Typical setup for measuring the effect of out-of-band signals on gain and noise temperature Equipped with XY
recorder
signal
indicator
additional instructions:
generator
coupler
GB11299.7-89
variable radio frequency
attenuator
amplifier
equipment configuration diagram 5 for measuring amplitude modulation/phase modulation conversion coefficient by static method
This standard is drafted by the 54th Institute of the Ministry of Electronics Industry. 82
phase meter7
Down conversion
Precision variable
Attenuator
Telecommunications
Indicator
Figure 2 Measurement equipment for hot/cold load Y-factor intermediate frequency variable attenuator method Sweep signal
Generator
Automatic level control
(according to setting)
Frequency signal
Generator
Attenuator
Hot: Cold
Isolator
Detector
Filter
Transmitted power
Input monitoring
(Set as needed)
Variable transmit
Attenuator
Reflected power defect sample
Directional coupler
(Reflectometer)
Detector and
Filter
ReflectometerTypical equipment configuration for measuring return lossRF converter
|Switch
Generator
Isolator
Amplifier
RF to
Switch
Downconverter
Amplifier
Use a short-circuit device to replace the amplifier under test during calibration
Amplifier or
Detector
Precision variable
Attenuator
Figure 4 Typical setup for measuring the effect of out-of-band signals on gain and noise temperature Equipped with XY
recorder
signal
indicator
additional instructions:
generator
coupler
GB11299.7-89
variable radio frequency
attenuator
amplifier
equipment configuration diagram 5 for measuring amplitude modulation/phase modulation conversion coefficient by static method
This standard is drafted by the 54th Institute of the Ministry of Electronics Industry. 82
phase meter
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